The Fermilab Neutron Program will continue to participate in the National Cooperative Neutron Studies with an anticipated protocol patient accrual of 15 patients per month. In addition, pilot studies will be undertaken in non-protocol patients. Specific tumors now felt to be most effectively treated with neutrons will be so managed outside of the protocol mechanism. Additional studies will be undertaken to further define the physical characteristics of the Fermilab neutron beam in relation to both the high LET and low LET components, and their biologic effects. Improvements will be accomplished in both beam control, and patient manipulation and immobilization.